Print hammer with integral pivotal print anvil

ABSTRACT

The printer includes a plurality of print wheels coaxially mounted for rotation about a common shaft and each including a metal disc provided with circumferentially spaced, embossed character bearing print members located at the disc periphery, and a plurality of pivotally mounted print hammers each having an anvil with a hammer surface which is selectively urgeable against its associated embossed character to produce at a print station, a character imprint on a record medium interposed along with a carbon ribbon between the hammer and the print wheel. One form of hammer includes an anvil which is pivotally mounted to the hammer body for the purpose of automatically compensating, every imprinting cycle, for nonparallelism between the hammer surface of the anvil and the plane of the embossed character at the point where they engage in imprinting relationship. Another form of hammer includes an anvil whose orientation can be selectively and permanently adjusted to eliminate nonparallelism between the hammer surface and a given character plane. Adjustment is accomplished by plastically deforming a wire which controls the orientation of the anvil relative to the hammer body. A method of fabricating the print wheels is disclosed which includes a placing holes at the center of the disc as well as at index points associated with the print member receiving positions whereat the print members are formed; mounted the disc in a molding device having a center post, an index post and a print member forming, or molding, cavity with the center and index posts engaging the center hole and an index hole, respectively, and with the print member receiving position of the disc positioned within the molding cavity; and introducing molten molding material into the cavity to form the print member at the print member receiving position inserting within the cavity.

United States Patent 1 91 Kleimeyer et al.

1 1 PRINT HAMMER WITH INTEGRAL PIVOTAL PRINT ANVIL [75] Inventors: Vernon T. Kleimeyer; Thomas J.

Schinner, both of Cincinnati, Ohio [73] Assignee: The Cincinnati Time Recorder Company, Inc., Cincinnati, Ohio [22] Filed: Jan. 13, 1971 21 Appl. No.: 106,227

Related US. Application Data [62] Division of Ser. No. 805,284, March 7, 1969, abandoned.

[52] U.S. Cl. ..l0l/93 C [51] int. Cl. ..B41j 9/02 [58] Field of Search ..101/93 C, 93 R, 379, 101/380, 405, 406, 28, 109

[56] References Cited UNITED STATES PATENTS 654,464 7/1900 MacAlester 101/406 1,284,446 11/1918 Potts ..10l/406 1 ,640,414 8/1927 Lake 101/406 1,789,832 1/1931 Pannier et a1. ..l01/406 2,887,043 5/1959 Terry ....101/93 R 3,063,364 11/1962 Kahlen ..101/28 3,139,820 7/1964 Kittler ....l01/93 C 3,215,068 11/1965 Ungman ....lO1/93 R 3,309,989 3/1967 Solheim et a1. ..10l/93 C 3,351,007 11/1967 Poland ..101/93 C 3,353,482 11/1967 Sariti ....lOl/93 C 3,568,593 3/1971 Papadopoulos 101/93 C Primary Examiner-William B. Penn A Home Wood, Herron & Evans 1 Apr. 17, 1973 A881 RACT The printer includes a plurality of print wheels coaxially mounted for rotation about a common shaft and each including a metal disc provided with circumferentially spaced, embossed character bearing print members located at the disc periphery, and a plurality of pivotally mounted print hammers each having an anvil with a hammer surface which is selectively urgeable against its associated embossed character to produce at a print station, a character imprint on a record medium interposed along with a carbon ribbon between the hammer and the print wheel. One form of hammer includes an anvil which is pivotally mounted to the hammer body for the purpose of automatically compensating, every imprinting cycle, for nonparallelism between the hammer surface of the anvil and the plane of the embossed character at the point where they engage in imprinting relationship. Another form of hammer includes an anvil whose orientation can be selectively and permanently adjusted to eliminate nonparallelism between the hammer surface and a given character plane. Adjustment is accomplished by plastically deforming a wire which controls the orientation of the anvil relative to the hammer body. A method of fabricating the print wheels is disclosed which includes a placing holes at the center of the disc as well as at index points associated with the print member receiving positions whereat the print members are formed; mounted the diSC in a molding device having a center post, an index post and a print member forming, or molding, cavity with the center and index posts engaging the center hole and an index hole, respectively, and with the print member receiving position of the disc positioned within the molding cavity; and introducing molten molding material into the cavity to form the print member at the print member receiving position inserting within the cavity.

1 Claim, 15 Drawing Figures Patented April 17, 1973 3,727,548

5 Sheets-Sheet 1 INVENTOR.

Patented April 17, 1973 3,727,548

5 Sheets-Sheet 2 INVENTOR.

%M/ BY/QC a???) Patented April 17, 1973 3,727,548

3 Sheets-Sheet 5 LO IP'Z37 Q INVENTOR,

PRINT HAMMER WITH INTEGRAL PIVOTAL PRINT ANVIL This application is a division of parent application more particularly to apparatus and methods of manufacturing of the type involving rotatably indexable print wheels with peripherally located embossed character bearing print members and cooperating selectively actuateable hammers, the print hammers being movable into imprinting relationship with the embossedcharacters for providing character imprints on a record medium which is disposed at a print station intermediate the hammer and print wheel.

In a number of information and data recording applications it is desirable to provide a printed record of the time and date of a particular transaction as well as a printed record of certain additional data identifying the transaction. Forexample, it is often desirable to provide a printed record of the time and date an employee reports to work alongwith the employees identification number. Such information is useful for payroll preparation and employment record keeping purposes. Illustrative of such an employee record keeping system is the system disclosed in Gieringer et al. US. Pat. No. 3,388,403 Employee Identification Card Recorder" issued June 11, 1968, and assigned to the assignee of this application.

Printers useful in employee record keeping systems of the type noted above typically. include a plurality of coaxially mounted metal plates having embossed characters representing the time and date. engraved in the peripheral edges thereof. The edge-engraved plates are incrementally driven past a print station in association with a record medium by a suitable clock mechanism such that at any given time .the embossed characters present at the print station reflect the proper minute, hour and date. Each employee has an identification card bearing, in embossed character format, has name and employee identification number. When the employee inserts his card into the printer for the purpose of making a record, a suitably provided platen within the printer is operated. The platen urges the record medium, which may be a paper tape and associated carbon ribbon, into imprinting relationship with the embossed time and date indicating characters engraved on the print wheel peripheries, producing on the record tape a print-out of the time and date of card insertion. The platen also urges the embossed card and record medium into imprinting relationship, producing a print-out of the employees name and number on the record tape adjacent the time and date print-out.

The time and date print wheels heretofore known have been unduly costly to manufacture by reason of the amount of time required to engrave the embossed characters in the periphery of the metal plate. Accordingly, it has been an objective of this invention to provide a print wheel which eliminates the need for costly and time-consuming character engraving heretofore necessary with prior art print wheels, but yet does not compromise the strength and configurational stability which characterized theall metal engraved print wheel heretofore known. This objective has been accomplished in accordance with certain of the principles of this invention by providing a print wheel of com posite construction wherein a disc having a plurality of peripherally located print member receiving positions is provided with a plurality of character-bearing print members each secured to the disc at different ones of the peripherally spaced print member receiving positions, the disc being fabricated of metal and the print members of material moldable in place at the disc periphery whereby they are simultaneously secured to the disc and their embossed characters formed.

The composite construction print wheel of this invention, by using print members formed of moldable material, eliminates the engraving required with prior art print wheels of all-metal construction. Yet, the strength of the print wheel, as well as its configurational stability which is critical with large diameter wheels having numerous characters thereon, are not sacrificed or otherwise compromised. Additionally, the composite construction print wheel of this invention does not require that the thickness of the disc equal the width of the embossed characters as is the case with the prior art all-metal construction print wheels wherein character width dictates disc thickness. Thus, with the composite construction of this invention, the thickness of the metal disc can be held to a minimum consistent with strength, while character width can be independently varied in excess of the disc thickness, as desired. Stated differently, it is unnecessary, with the composite print wheels of this invention, to use disc thicknesses in excess of that required for strength just to accommodate wide characters. Finally,'the composite print wheels of this invention permit the embossed print members and their associated characters to be formed on the metal disc one at a time, thereby enabling use of a single cavity print member molding device. By eliminating the need for multi-cavity molds, the cost of the molding equipment necessary to form the embossed character bearing print members of this invention may be kept to an absolute minimum, if desired. This is particularly desirable where large volume production is not initially present. to justify the immediate expense of multiple-cavity molds.

It has been another objective of this invention to provide a method of fabricating the composite print wheels of this invention which is inexpensive, rapid and requires a minimum investment in tooling. This has been accomplished in accordance with further principles of this invention by providing a print wheel fabrication method including the steps of forming in a rigid plate, preferably a stamping of sheet metal stock, aho'le in the center as well as a plurality of index holes at index points associated with the plate print member receiving positions; thereafter mounting the apertured plate in a molding device having a center post, an index post and a molding cavity with center and index posts engaging the center hole and an index hole, respectively, and with a print member receiving position inserted in the molding cavity; and, finally, introducing molding material into the cavity to simultaneously form the print member, including the embossed character thereon, and secure the formed print member to the plate.

An advantage of the foregoing method is that a molding device having only a single molding cavity may be used, thereby minimizing the cost of the molding equipment.

It has been a further objective of this invention to provide a print hammer which automatically compensates for differences in character plane angulation of various print members on the same print wheel. In order to obtain a satisfactory imprint of the embossed character on the record member it is essential that the print hammer, at the point it strikes the embossed character, have its hammer surface parallel to the plane in which the embossed character lies. In this manner, equal and uniform pressure is applied by the hammer to all portions of the embossed character providing an imprint on the record medium of uniform quality. If the character planes of all characters on a given print wheel are identically oriented, then by making one adjustment for hammer surface angulation, the desired striking angle is reproduced each time the hammer strikes a different embossed character. Unfortunately, in some cases the character planes of characters on a given wheel are not identically oriented, and if the hammer surface angle is adjusted to strike one character in parallel fashion it will not be parallel with respect to another character having a differently oriented character plane.

Accordingly, it has been an objective of this invention to provide a print hammer which, regardless of differences in the character plane orientations of the characters ofa single print wheel, strikes all characters in a parallel fashion to provide uniform imprinting pressure over the entire surface of the struck characters. This objective has been accomplished, in accordance with still further principles of this invention, by providing a print hammer which includes an elongated hammer body and an anvil connected thereto by means which permit the anvil to move relative to the hammer body when it strikes the embossed character, thereby permitting it to align itself parallel to the character plane as the-hammer completes the imprinting cycle. In a preferred form of hammer having such a compensating feature the hammer body, anvil, and connecting means are integral with the connecting means taking the form of a neck having a cross section significantly smaller than the cross sections of either the anvil or the hammer body at the points thereof to which the connecting neck is joined. In other embodiments the con-. necting means takes the form of a pin-joined tongue and groove connection, and a snap-in ball and socket type joint.

An advantage of the striking angle compensating hammer of this invention, in addition to being able to compensate for differences in character plane orientation for different print members of the same print wheel, is the ability to compensate for differences in character plane orientations of differing diameter print wheels which, while the same for characters of a given wheel, are different for different diameter print wheels. Thus, identical hammers can be used with different diameter wheels without need for adjusting each hammer to its respective different diameter print wheel.

A further objective of this invention has been to provide a hammer which permits the angulation of the hammer surface of the anvil to be permanently adjusted relative to the hammer body. This objective has been accomplished in accordance with further principles of this invention by providing a print hammer including an elongated hammer body having a longitudinal slot which divides one end region thereof into a first section mounting an anvil and a second section, and an adjustment means contacting the first and second end region sections for selectively altering the disposition of the first and second sections relative to each other, and hence of the anvil relative to the remainder of the hammer body. In a preferred form, the adjustment means is a plastically deformable wire having its ends anchored in different ones of the end regions whereby the end regions assume the orientation relative to each other established by the configuration of the plastically deformable wire. With such an arrangement merely by deforming the wire it is possible to alter the angular disposition of the hammer surface of the anvil with respect to the remainder of the hammer structure.

These and other objectives and advantages of the invention will become more readily apparent from a detailed description of the invention taken in conjunction with the drawings in which:

FIG. 1 is a perspective view of a printer constructed in accordance with the principles of this invention.

FIG. 2 is a side elevational view of a preferred form of print wheel constructed in accordance with the prin ciples of this invention.

FIG. 3 is a cross-sectional view taken along lines 3- 3 of FIG. 2.

FIGS. 4A, 4B and 4C are side elevational views of one form of print hammer of this invention, showing the various manners in which the anvil thereof can be adjusted.

FIGS. 5, 6 and 7 are perspective views of three different print hammer embodiments each of which automatically compensates during the imprinting cycle, for character plane misalignment.

FIGS. 8, 9 and 10 are side elevational views of the print hammer of FIG. 5, showing the manner in which it compensates for varying character plane angulation.

FIGS. 11, 12 and 13 are respectively a prospective I view, plan view, and cross-sectional view of apparatus for fabricating embossed character assemblies of the type with which the hammer of this invention is particularly useful.

A printer 100 embodying certain of the principles of this invention is depicted in FIG. 1. The printer 100 includes a plurality of print wheels 101 coaxially mounted for rotation about a common shaft 104. The

print wheels 101 are preferably circular, but may be in the form of a segment ofa circle or the like. Each of the print wheels 101 includes a plate or disc 102, and at least one print member 105 located at circumferentially spaced print member receiving positions 106 on the circular peripheral edge 107 of the plate or disc. The print members 105, of which there are preferably a plurality, are relatively permanently fixed or secured in their respective print member receiving positions 106 in a manner to be described hereafter, and are each provided with embossed indicia 108 which preferably includes a numeric or alphabetic character 108(a) and a coded representation 108(b) of the numeric or alphabetic character. The embossed indicia 108 of the print members 105 lies in a character plane 109 which preferably is perpendicular to a radial line 110 in the plane of the plate or disc 102 and passing through the center of the print member 105.

In operation, incremental drive means (not shown), for example a clock mechanism, selectively increment the print wheels 101 angularly about the shaft 104 to selectively position a desired one of the print members 105 of each print wheel 101 at a print station 114 in operative imprinting relationship to associated print hammers 117, a carbon ribbon 119, and record medium 120. With the desired print members 105 of each of the print wheels 101 so positioned at the print station 114, an imprint 103 of the embossed indicia 108 associated the positioned print members can be produced on the record medium 120. Imprinting occurs when the hammers 117, which are pivotally mounted on a common shaft 134, are rotated by suitable means (not shown) from an inoperative position wherein the hammers are spaced from the carbon ribbon (see center and right hand hammers) to an operative position wherein the hammers, print'members 105, carbon ribbon 119 and record medium 120 are urged into imprinting relationship (see left hand hammer).

A preferred form of print wheel 101, as seen more particularly in FIGS. 2 and 3, includes the circular plate or disc 102. Disc or plate 102 is fabricated of material characterized by having good impact resistance, dimensional and configurational stability, and sufficient strength and rigidity to permit use of relatively thin plates. A suitableplate material has been found to be aluminum sheet stockhaving a thickness of approximately 0.067 inch, marketed by Alcoa Corporation under the trademark Alclad 7075-T6". In accordance with the preferred plate fabrication technique of this invention, the plate 102 is stamped from sheet aluminum stock utilizing conventional sheet metal stamping apparatus.

The plate 102, as shown in FIG. 2, also includes a hole 118 formed in the central region of the disc, for the example at the center thereof, and includes a plurality of circumferentially spaced locaters, or indexholes, 121 corresponding in number to the number of print members 105 and each located at an index point in association with a different print member.

Preferably, the index holes 121 are each equally radi- I ally displaced from the centerof the plate 102, and are each centered on the respective radial lines 110 which pass through the center of their associated members 105. The function of the indexholeslZl. will become more readilyapparen t hereafter in conjunction with a i. detailed description of the preferred method of fabricating the print wheels 101.

The plate 102 further includes a plurality of surface discontinuities 123, the function of which will also become apparent later. These discontinuities 123 correspond in number to the number of print members 105, and are each associated with a different print member receiving position 106. Discontinuities 123 are located such that each discontinuity has at least a section thereof within the print member receiving position 106 with which it is associated. Preferably the discontinuities 123 are in the form of throughholes. However,

the discontinuities 123 may take the form of lugs or tangs projecting fr'om the surface of the plate 102. A preferred method of forming the holes 121 and the holes 123 is by use of conventional punch and dieor metal stamping techniques. Alternative hole forming methods, however, may beused such as drilling.

Each print member as shown in FIG. 3, includes substantially planar parallel sections 125 and 126 disposed on opposite sides of the plate 102 in sandwiching relationship to that portion of the plate which constitutes the print member receiving position 106. The print member 105 further includes a character receiving section 127 disposed radially outwardly of the peripheral edge 107 of the plate 102 and between i the planar sections 125 and 126. Fixed to an outer surface 128 of the character receiving section 127 are the embossed characters 108(a) and 108(b). The embossed characters 108(a) and 108(b) are preferably located in the character plane 109 defined earlier as being the plane perpendicular to the radial line 110 lying in the plane of the plate 102 and passing through the center of the print member 105. The print member 105 also includes a lock member 129 passing through the plate hole 123 and interconnecting the planar print member sections 125 and 126. The print member 105 in a preferred form, the method of fabrication of which is described hereafter, is integral in construction.

The print hammer 117, depicted more particularly in FIG. 4A, includes an elongated body 132 having a lower end and an upper end 138. The lower end 130 includes an aperture 133 (FIG. 1) to facilitate mounting for rotation about the transverse shaft 134. The upper end 138 of the hammer body 132 is divided into two equal sections 138(a) and 138(b) by a longitudinal slot 136 through the center thereof. Projecting from an upper end section 138(a) of the hammer body 132 is an anvil 116 having a substantially flat hammer surface 115. The slot 136 in conjunction with a removed or relieved section 137 formed in the central portion of the body 132 adjacent the upper end section 138(a) provides a necked or reduced cross-section region 139 between the anvil 116 and the central portion of the hammer body. The necked region permits the anvil 116 topivot slightly about its lower end relative to upper end section 138(b) for reasons to be described hereafter.

The print hammer further includes a U -shaped wire 140 having its lower ends 141 and 142 securely encased or anchored in the upper end sections. 138(a) and 138(b) ofthe hammer body 132. The ends 141 and 1-42 of the U-shaped wire 140 may be anchored in i hammer body sections 138(a) and 138(b) by insertionthereof in suitably provided longitudinally disposed by suitable means, for example, by urging the upper portions 143and 144 thereof toward or away from each other, the U-shaped wire remains in the configu-. 'ration or shape to which it is plastically deformed (see FIGS. 48 and 4C). This, in turn, maintains ,the anvil 116 in a predetermined position relative to the upper right handportion 138(b) of the hammer body 132 in accordance with the degree and extent to which the U- shaped wire is plastically deformed: By virtue of the plastically deformable nature of the wire 140 and the flexible character of the neck region 139, theangular disposition of the hammer surface 115 of anvil 116 relative to hammer body 132 may be varied or adjusted to accomodate slight variations in the angular disposition of the character planes 109 of a print wheel 101 relative to a radial line 110 passing through the center of the print members 105 of the wheel with which the print hammer 117 is associated. Thus, a print hammer 117 is provided having an anvil 116 which, within a range, can be relatively moved such that its hammer surface 115 assumes different relatively permanent dispositions with respect to its associated print wheel.

FIGS. 5, 6 and 7 depict alternative embodiments of print hammers which automatically compensate, from print member to print member on the same print wheel, for deviations from perpendicularly of the character planes 109 with respect to their radial lines 110 through the centers thereof. The print hammer 150 depicted in FIG. includes an elongated body 151, the lower end of which (see FIGS. 8-10) is mounted for pivotal movement about a transverse shaft such as a shaft 134, to permit the upper end 152 of the print hammer to be moved between inoperative and operative imprinting positions. The upper end 152 of the print hammer 150 includes the elongated anvil 153 having a hammer surface 154. The anvil 153 is movably connected to the upper end 152 of the hammer body 151 of hammer 150 by connecting means 155 having a vertical cross section which is significantly less than the vertical cross section of either the anvil 153 or. the

upper end 152 of the hammer body 151 to which the connecting means 155 is secured at spaced points.

In a preferred form of the print hammer 150, the anvil 153 and hammer body 151, as well as the connector 155, are integral. With such an integral print hammer structure, the connector 155 takes the form of a neck interconnecting the anvil 153 and the upper end 152 of the rigid member 150. The connecting neck 155 is established by providing upper and lower slots 156 and 157 on either side thereof. The slots may be formed at the time the integral print hammer structure 150 is molded, if molding techniques are used to fabricate the print hammer. Alternatively, the print hammer structure 150 may first be formed without the slots 156 and 157, and thereafter the slots 156 and 157 provided by sawing or the like. To permit the anvil 153 to pivot about the connecting neck 155 in both a clockwise and a counterclockwise direction, as viewed in FIG. 5, the connecting means 155 is preferably located intermediate the upper and lower ends 158 and 159 of the anvil. In accordance with the preferred placement of the connecting means 155, the anvil 153 can rotate both clockwise and counterclockwise about the connecting neck 155, and accordingly can provide bidirectional compensation in a manner to be described.

FIGS. 8, 9 and 10 in which the record medium and carbon ribbon are removed for clarity, depict the manner in which the print hammer embodiment 150 of FIG. 5 operates to compensate for differences in perpendicularly of the character planes 109 of a given print wheel 10] relative to their associated radial lines 110. Specifically, FIG. 8 depicts a print wheel 101 having a pair of embossed characters 108(a) and 108(b) which lie in a character plane 109 which is ideally oriented, that is, perpendicular, with respect to its radial line 110 passing through the center of its associated print member 105. With the character plane 109 so positioned and the hammer mounting shaft 134 appropriately located, when the hammer 150 is rotated counterclockwise (as viewed in FIG. 8) to its operative imprinting position to urge the anvil 153 against the print member 105, the anvil 153 at the instant it begins striking the print member 105 will have its hammer surface 154 disposed parallel to the character plane 109. With the hammer surface 154 initially so disposed upon striking, equal imprinting forces are applied by the anvil 153 to both the upper character 108(a) and the lower character 108(b) without need for pivotal compensating movement of the anvil 153.

In FIG. 9 the orientation of the character plane 109 of the print member 105 departs from the idealized condition to the extent that the character plane 109 is not perpendicular to the radial line 110 passing through the center of its associated print member 105, but rather is angled thereto at some angle A which is less than With the character plane 109 so angled, as the print hammer 150 is initially rotated counterclockwise (as viewed in FIG. 9) into operating position, the lower portion of the hammer surface 154 contacts the lower embossed character 108(b) before the upper hammer surface portion contacts the character 108(a). Continued counterclockwise motion of hammer 150 causes the movable anvil 153 to rotate counterclockwise about the connecting neck 155 until the upper section of the hammer surface 154 contacts the upper character 108(a), whereupon continued counterclockwise hammer motion results in the application by anvil 153 of substantially equal imprinting forces to both of the characters 108(a) and 108(b).

In FIG. 10 the character plane 109 of the print member also departs from the idealized perpendicular orientation. In this case, the character plane 109 is angled to the radial line passing through the center of its associated print member 105 at an angle B which is slightly in excess of 90. With the character plane 109 of the print hammer 105 depicted in FIG. 10 so angled, when the hammer is rotated counterclockwise the upper section of the hammer surface 154 contacts the upper character 108(a) before the lower section of the hammer surface 154 contacts the lower character 108'(b). However, continued counterclockwise rotation of the hammer 150 causes the anvil 153 to rotate clockwise about the connecting neck until the lower section of hammer surface 154 contacts the lower character 108(b) whereupon further counterclockwise motion of the hammer results in the application of substantially equal imprinting forces by the hammer surface 154 to both the upper and lower characters 108(a) and 108(b).

In addition to the hammer 150 being capable of compensating for differences in character plane orientation for print members 105 on the same printing plate 102, the print hammer compensating feature is also useful in other situations where compensation is necessary. For example, where coaxially mounted print wheels of slightly differing outside diameter are used in conjunction with coaxially mounted identically configured hammers 150, the character planes 109 of the different diameter print wheels will be located at different radial distances from the common print wheel center line. With the character plane radial position differing from print wheel to print wheel, and with identically configured print hammers 150 mounted on the same shaft 134 associated with the different coaxially mounted print wheels, the initial angle of the hammer surface 154 relative to the character plane 109 at the point in time when the hammer surface first contacts one of the characters 108(a) or 108(b) will differ from hammer to hammer. With the angle of initial hammer contact varying from hammer to hammer, the anvils 153 of the different hammers will rotate through different angles in the course of a complete counterclockwise hammer rotation and imprinting cycle to cause substantially equal forces to be applied by hammer surface 154 to the upper and lower characters 108(a) and 108(b).

In FIG. 6 an alternative embodiment of a print hammer 160 also capable of anvil compensating movement is depicted. Theprint hammer 160 includes an elongated hammer body 161, the lower end of which (not shown) is mounted for rotation about a suitable shaft for permittingthe hammer 160 to rotate counterclockwise into an operative imprinting relationship with a print member 105 of a suitably disposed print wheel 10]. The print hammer 160 further includes an anvil l63 having a hammer surface 164. The anvil 163 of FIG; 6, like the anvil 153 of FIG. is connected to the upper end 162 of the hammer body 161 by a suitable pivotal connector 165. The connectorl65 includes a tongue 166 formed integral with the anvil 163, and a slot 167 formed in the surface of the upper end 162 of the hammer body 161. The slot 167 is oversized relative to the tongue 166. to permit the tongue, when inserted in the slot and retained therein by a transverse pin 168, to pivot about the pin, in turn, enablingthe anvil 163 to pivot relative to the upper end 162 of the hammer body 161. The pivotally connected anvil 163 accommodates for differently oriented character planes of the same print wheel 101, and different radially positioned character planes of different diameter print wheels, in the same manner as theanvil 153 of print hammer 150.

Another alternative print hammer embodiment 170, having the compensating feature of print hammers 150 and 160, is depicted in FIG. 7. Print hammer 170 includes an elongated hammer body 171, the lower end of which (not shown) is mounted on a suitably disposed transverse shaft for hammer rotation into inoperative and operative imprinting positions. The upperend 172 of the hammer 170 has connected thereto an anvil 173 via a pivotal connection .175. The pivotal connection 175 includes a socket 176 formedin the upper end 172 of the hammer body 171 and a cooperating ball-type projection 177 formed integral with the anvil 173. The mating surfaces of the projection I77 and the socket 176 are similarly curved to permit the anvil 173 to pivot about a horizontal axis passing through the center of projection 172. This enables the hammer surface 174, when it strikes character 108(a) and 108(b) of a suitably positioned print member 105, to apply equal imprinting force to both characters. Upper and lower pins 178 and 179 projecting from the anvil 173 cooperate with suitably positioned blind holes 180 and 181 formed in the upper end 172 of the hammer body 171 to restrict relative lateral displacement between the anvil and the upper end of the hammer, body. The curved surface of the socket 176 extends through an are substantially in excess of 180 to permit the extension 177 to be snapped into operative position in the socket 176 and when so positioned in the socket to remain therein. By virtue of the pivotal connection 175 between the anvil 173 and the upper end 172 of hammer 171, the print hammer 170 compensates for different angularly oriented, and different radially positioned, character planes in a manner similar to print hammers 150 and 160.

Depicted in FIGS. 11, 12 and 13 is a preferred molding device 10 suitable for use in forming in place in their respective print member receiving position 106, the preferred integral construction print members 105 having characters 108(a) and 108(b) embossed thereon. The molding device 10 includes a molding cavity 11 which is formed when cooperating upper and lower mold heads 12 and 13 are brought into sandwiching relationship with respect to an appropriately positioned circular plate 102 interpositioned therebetween. The molding device 10 also includes a center post or locater l4 projecting from the lower molding head 13. Post 14 functions to locate, along a line 16 between the center of the post 14 and the center of an embossed character die 34, the print receiving position 106, whereat the print member is to be formed, relative to surface of the embossed character die 34 which bears the engraved characters 15(a) and 15(b) of the character die 34. Also included in the molding device 10 is a loca'ter or index post 17 which functions to angularly orient the print member receiving position 106, whereat the print member 105 is to be formed, relative to the cavity 11.

The upper molding head 12 includes noncoplanar parallel surfaces 19 and 20 which are connected to each other by planar contiguous wall sections 21, 22,

23, 24 and 25. Wall sections 21-25 are disposed substantially perpendicular to the parallel non-coplanar surfaces 19 and 20. Contiguous wall sections 22-24 constitute the upper wall sectionsof three side walls of the cavity 11, while the portion of the planar surface 19 partially enclosed by contiguous walls 22 -24 defines the upper surface or top of the cavity. The lower mold head 13 includes parallel non-coplanar surfaces 26, 27 and 28. Connecting surfaces 26 and 27, and disposed perpendicular thereto, are non-contiguous coplanar surfaces 29 and 33. Connecting surfaces 27 and 28 are contiguous surfaces 36, 37 and 38 which are disposed perpendicular thereto.

Surfaces 30, 31 and 32, as well as a portion of surface 28,provide a recess which is substantially filled by the interfitting embossed character die 34 which has the engraved characters 15(a) and 15(b), to be embossed, in its surface 15.

Surfaces 36, 37 and 38 as well as the exposed portions of surfaces 30 and 32, thatis, those portions of surfaces 30 and 32 which do not mate with the sides of the embossing die 34, constitute, along with walls 22-24, additional side walls of the cavity 11. Thus, the side walls of the cavity 11 are the engraved surface 15, the exposed portions of parallel wall sections 30 and 32 which are perpendicular to and contiguous with the engraved surface 15 and disposed on opposite sides thereof, coplanar upper and lower surfaces 24 and 38, coplanar upper and lower surfaces 23 and 37, and coplanar upper and lower surfaces 22 and 36. The bottom of the cavity 11 is defined by that portion of surface 28 bounded by wall sections 36, 37 and 38, engraved surface 15, and the exposed sections of walls 30 and 32. The upper surface of the cavity 11, as noted previously, is that portion of surface 19 enclosed by contiguous walls 22, 23 and 24. The vertical dimension of wall sections 36, 37 and 38 establishes the depth of the cavity 11 below the lower surface 40 of a plate 102 properly positioned in the molding device 10, and is equal to the thickness of planar sections 125 and 126 of print member 105 (FIG. 3). The vertical dimension of walls 22, 23 and 24 establishes the height of the cavity 11 above the upper surface 41 of the disc 102 properly positioned in the molding device 10, and is also equal to the thickness of the planar sections 125 and 126 (FIG. 3). The vertical dimension of walls 29 and 33 establishes the height of the entire cavity 11 and is equal to the sum of the height of walls 36-38, the height of walls 22-24, and the thickness of the plate 102.

The circular cross-section post 14 is permanently fixed to the surface 27 of the lower mold head 13 and has a diameter equal to the diameter of the hole 118 formed in the center of the plate 102 (FIG. 2). The position of the post 14 along the line 16 passing through the center of the engraved surface and the center of the post 14 is selected such that the peripheral edge 107 of the disc 102 when mounted on post 14 contacts the vertical corner edges 60 and 61 formed by the intersection of walls 29 and 30 and walls 32 and 33, respectively. The index post 17 is dimensioned to pass through the index holes 121 (FIG. 2) formed. in the disc 102 and be removably positioned in a blind hole 43 into which the lower end of the post 17 interfits. The location of the hole 43 relative to the cavity 11 and the center post 14 is such that, when the post 17 is inserted through the index hole 121 of a disc mounted on the center post 14, the print member receiving position 106 associated with the hole 121 into which the index post 17 is positioned will be properly positioned within the cavity 11. It is apparent that as a disc 102 mounted on the post 14 is rotated about the post, bringing into register successive ones of the circumferentially spaced index holes 121 with the hole 43, successive ones of the print member receiving positions 106 will be successive and properly registered with the cavity 11,

The molding device 10 includes a pair of locating pins 46 and 47 projecting downwardly from surface 19 of the upper mold head 12, and cooperating locating holes 44 and 45 in the surface 26 of the lower head 10. The locating pins 46 and 47 when engaged in their respective locating holes 44 and 45 properly position the mold heads 12 and 13 for a print member molding operation. When so operatively positioned, surfaces 21 and 25 contact surfaces 29 and 33, respectively, and surfaces 22, 23 and 24 are coplanar with surfaces 36, 37 and 38, respectively. The upper mold head 12 is also provided with an open slot 50 which loosely receives the upper end of the indexing post 17 when the mold heads are operatively positioned in sandwiching relationship with respect to a disc 102 properly mounted on the post 14.

In operation, the molding heads 12 and 13 are initially separated and the indexing post 17 removed.

With the heads 12 and 13 separated and the post 17 removed, a disc 102 on which it is desired to form the print members is mounted such that its lower surface 40 is flush with the surface 27 of the lower die head 13 and the post 14 passes through the plate center hole 118. The disc 102 is then angularly rotated about the post 14 until the index hole 121 associated with the print member receiving area 106 whereat the print member is to be formed is aligned with the hole 43, whereupon the index post 17 is inserted through the index hole 121 into the blind hole 43. At this point the print member receiving position 106 associated with the index hole 121 in which the index post 17 is inserted is aligned with and overlying the lower portion of the cavity 11 with the peripheral plate edge 107 in contact with the vertical edges 60 and 61 constituting the intersection of wall sections 29 and 30 and wall sections 32 and 33. Final assembly of the molding device 10 is effected by superimposing the upper and lower mold heads 12 and 13, and thereafter bringing them into sandwiching relationship with respect to the interposed plate 102 such that the locating pins 46 and 47 engage locating holes 44 and 45, surface 19 contacts surface 26, surfaces 21 and 25 contact surfaces 29 and 33, respectively, and surface 20 contacts the upper surface 41 of the disc 102.

With the molding device assembled in the foregoing manner, the molding device is then operably associated with suitable injection molding equipment (not shown). Once associated with the injection molding equipment, the molding heads 12 and 13 are clamped together, and a source of molten forming material, such as plastic, is connected to the outer end 52 ofa passage 53 formed in the molding head 12, the lower end 54 of which connects to an elongated open groove 55 formed in surface 19. Groove 55, in conjunction with an underlying portion of the surface 26 and an underlying portion of the upper surface of the embossing die 34, forms a plastic flow passage interconnecting the mold cavity 11 and the molten plastic entry passage 53. Molten plastic under pressures consistent with known injection molding processes is now introduced into the passage 53 whereupon it flows through passage including the elongated groove 55 into the cavity 11, filling that portion of the cavity 11 not occupied by the inserted print member receiving section 106 of the plate 102. The molten material in the cavity 11 is then permitted to cool. Following cooling, the mold heads 12 and 13 are separated, the index post 17 removed, and the disc 102 temporarily raised and angularly indexed until the index hole 121 associated with the next print member receiving position 106 whereat a print member 105 is to he formed is aligned with the hole 43. The post 17 is then inserted through the aligned hole 121, the index heads 12 and 13 assembled and clamped, and the molten material introduced into the cavity to form the print member 105 with its embossed characters 108. The foregoing steps are repeated until all desired print members 105 have been formed on the disc 102.

Of course, it will be understood by those skilled in the art that if different embossed characters are to be provided at different positions 106 of the same disc 102, the embossing die 34 must be changed after each print member 105 is formed if the print members 105 are to be successively formed without removing the plate from the molding head 13. To avoid unnecessary changing of character dies 34, when multiple print wheels of identical character content are to be formed, identical characters of each print wheel are formed in succession and the die then changed and the sequence repeated for the new character. Of course, while this practice increases the total time spent mounting and dismounting the plates 102 on the center post 14, such increase is more than compensated by the time saved in character die changing.

As those skilled in the art will appreciate, a number of different formable materials may be used for fabricating the print members 105 including the embossed characters 108. One formable material found to be satisfactory is a plastic of the acetal resin type marketed by E. l. Dupont deNemours and Co. under the trademark DELRIN 500." Other formable materials in addition to DELRIN 500 may be used providing they have good resistance to impact.

The hammers 150, 160 and 170 shown in FIGS. 5,6 and 7, respectively, have anvils 153, 163 and 173, respectively, which are mounted for bidirectional pivoting motion in a single plane by connecting means 155, 165 and 175, respectively. As those skilled in the art will appreciate, the anvil connecting means 155, 165 and 175 could be designed to provide compensating motion of a nature which is not limited to bidirectional pivotal movement in a single plane. For example, the connecting neck 155 of hammer 150 could be undercut on both sides thereof to further reduce the cross section of the connector and permit the anvil 153 to pivot bidirectionally in a plane substantially perpendicular to the plane for which it is now designed to pivot. In the hammer embodiment of FIG. 7, the connecting means 174 could take the form of a true ball and socketjoint, and if such connecting means were used the anvil 173 would have universal-type pivoting motion.

The hammers 117, 150, 160 and 170 can be fabricated of any stiff material having suitable impact resistance. A material found suitable is the plastic marketed by E. l. Dupont deNemours Co. under the trademark DELRIN 500," noted previously.

The plate index holes 121 and cooperating index post 17 of the molding device may be replaced by providing on the plate 102 suitable lugs at each of the index hole locations. The lugs would interfit in the hole 43 and thereby achieve the necessary angular indexing of the plate 102 relative to the cavity 11.

The holes 123 formed in the plate 102 at each of the print member receiving positions 106 could be replaced by notches formed in the plate edge 107. Preferably the notches would have a width which increases with decreasing radial distance from the center of the plate.

Having described this invention, what I desire to claim by Letters Patent is:

1. An integral print hammer for urging a record medium into imprinting relationship simultaneously with first and second adjacent embossed characters formed on a print wheel and lying in a given character plane perpendicular to a radial line of said print wheel, comprising:

a hammer body movable between an imprinting position and an inolperative position, and an anvil integral y connected to said hammer body and having first and second hammer surfaces adapted to urge said embossed first and second characters, respectively, and record medium into imprinting relationship when said hammer body is moved to its imprinting position, said connection between said anvil and hammer body being a necked section of said print hammer integral with said anvil and hammer body and located therebetween and substantially equidistant from said first and second hammer surfaces, said necked section also being located between a pair of first and second open-ended slots, which first and second slots are also located between said anvil and hammer body, and behind said first and second hammer surfaces, respectively, said integral necked connection being adapted to permit relative bidirectional pivotal movement between said anvil and hammer body to enable said first and second hammer surfaces to become aligned parallel with said first and second characters of said character plane and apply equal printing force to said adjacent characters in a given printing stroke when said hammer body urges said anvil into imprinting relationship with said characters. 

1. An integral print hammer for urging a record medium into imprinting relationship simultaneously with first and second adjacent embossed characters formed on a print wheel and lying in a given character plane perpendicular to a radial line of said print wheel, comprising: a hammer body movable between an imprinting position and an inoperative position, and an anvil integrally connected to said hammer body and having first and second hammer surfaces adapted to urge said embossed first and second characters, respectively, and record medium into imprinting relationship when said hammer body is moved to its imprinting position, said connection between said anvil and hammer body being a necked section of said print hammer integral with said anvil and hammer body and located therebetween and substantially equidistant from said first and second hammer surfaces, said necked section also being located between a pair of first and second open-ended slots, which first and second slots are also located between said anvil and hammer body, and behind said first and second hammer surfaces, respectively, said integral necked connection being adapted to permit relative bidirectional pivotal movement between said anvil and hammer body to enable said first and second hammer surfaces to become aligned parallel with said first and second characters of said character plane and apply equal printing force to said adjacent characters in a given printing stroke when said hammer body urges said anvil into imprinting relationship with said characters. 